Performance and the Sage 300 Views Part 1

The Sage 300 ERP Views (Business Logic) give you a great deal of power to perform Accounting operations through our various APIs. However as in any programming, performance must always be taken into account. The Sage 300 ERP Views have a lot of features to help you perform operations with good performance, but like anything if they are used incorrectly, performance can be miserable.

This article is going to talk about various features and options that you can take advantage of to improve your application’s performance. As I am writing the article, it’s getting quite long, so I think I’m going to break it into two parts.

Measure and Test

One of the big mistakes people make when performance tuning, is to just make assumptions and changes without doing real measurements. If you have your code in a source control system, first establish a base line for how long something takes, then make you changes and re-measure the time. Only check in your changes if the time is faster, if it isn’t then you are just churning your code and potentially adding bugs. Performance is subtle and often the best ideas and intentions just make a process slower.

Multi-User versus Single-User Performance

This article is about optimizing processes for single users. Often if you want to optimize better multi-user throughput then it’s all about reducing locks and keeping resource usage down. Sometimes these goals align, i.e. 1 person doing something quicker translates to 100 people doing things quicker, sometime they are opposing, i.e. one person can do something way quicker if he takes over all available resources at the detriment to everyone else.

Read-Only versus Read-Write

You can open our database links and views either in read-write mode or read-only mode. Generally if you aren’t updating the data then you want to open in read-only mode as this makes things quite a bit faster. If you might update the data then we have to use more expensive SQL operations so that if you do update the data, the update is fast and multi-user considerations are handled. If you open a table or link read-only then we use much lighter weight SQL operations and the data is returned much quicker. Finders use this to display their data quicker.

FilterSelect/FilterFetch versus Browse/Fetch

When you Browse/Fetch you can always update or delete the record fetched. As mentioned above that can introduce extra overhead and slow things down. Making the table or link read-only will help Browse/Fetch, but perhaps a better method is to use the FilterSelect/FilterFetch methods which are better optimized for SQL Server than Browse/Fetch. The results from these can’t be updated or deleted but at the same time the access method is always light weight whether the link is open read-only or read-write.

Indexes

Sage 300 will always use an index to read data. We have a lot of code to optimize access based on available indexes. If you use the indexes provided your code will be much faster.

For example, suppose you want to know if there are any open G/L Batches. A quick bit of code to do this is:

This works pretty good on sample data, but then you go to a client, suddenly this becomes quite slow. The reason is that since BATCHSTAT isn’t part of the primary index, the GoTop basically goes looking through the Batch table until it reaches the end or finds an open batch. Since open batches are usually at the end, this tends to be sub-optimal. Practically you could speed this up by searching through the table backwards since then you would probably find one quicker, but if there are no open batches you still search the whole table. Fortunately there is a better way. The GLBCTL table has two indexes, one is its primary default index of BATCHID and the other secondary index is on BATCHSTAT and BATCHID (to make it an index without duplicates). So it makes sense to use this index:

Simple adding the Order property makes this search much quicker. I included a sample program with timers and the full code. The results on sample data show the speed difference (not that it was all that slow to start with):

Time to determine if there are open batches: 00:00:00.034
Time to determine if there are open batches take 2: 00:00:00.007

The sample program is located here. Its PerformanceSamples one (folder and zip).

So generally you want to use an index that matches the fields that you are searching on as much as possible. Usually having clauses in your browse filter that uses the index segments from left to right will result in the fastest queries.

This example may look a little artificial, but once you get into the operational modules like O/E and P/O this becomes crucial. That is because the main tables like the Order Header have a uniquifier as the primary index. When you want to look something up it’s usually by something like order number and to do this efficiently you have to use an alternate index. So once you are using these modules you will be using alternate indexes a lot. In these modules also be careful that quite a few alternate indexes allow duplicates, so you might get back quite few records unexpectedly.

RVSpy/DBSpy

RVSpy and DBSpy are good tools for identifying bad behavior. The logs contain time information so you can see where the time is being used, but more often than not doing something bad for performance results in a series of operations appearing over and over in these logs. Usually scrolling to the middle of the output file is a good way to see something going awry. You can also use SQLTrace or ODBCTrace, but I find these slightly less useful.

When using RVSpy for this purpose, it helps to turn off logging to a Window (slow) and only log to a file (make sure you specify one). Further choose the View calls you want to log, usually disabling anything to do with meta-data and anything that is field level.

Most of this article is about avoiding table scans, but just to re-iterate table scans are bad. People are often fooled by testing on sample data. Many of the tables in sample data are quite small and it doesn’t really matter what you do. However in the real world with real customer databases things will usually be quite different. For instance sample data has 9 tax authorities, which you might think is reasonable. But in the USA where any municipal government agency can charge a sales tax, there are over 35,000 tax authorities. If you read all these (like to populate a combo-box to pick one from), then you will run very slowly and your customers will be unhappy.

Summary

Sage 300 ERP has many mechanisms to access and manipulate data efficiently. But as with anything in programming, if you use APIs without due care and attention then performance (and quality in general) will suffer.

5 Responses

[…] Introduction The Sage 300 ERP Views (Business Logic) give you a great deal of power to perform Accounting operations through our various APIs. However as in any programming, performance must always… […]

Steve, I have a question not directly related to Views, but more related to your discussion of indexes above….I’m wondering, is it EVER acceptable to add our own indexes in SQL to an Accpac table to improve performance?

Perhaps you’ve written some code that, for various reasons, has to access a table thru a field not included in one of the out-of-the-box primary or secondary indexes. Or perhaps a critical report needs to be sped up. Or some other reason that an operation must be performed on a non-indexed field. Is there an absolute prohibition against adding our own indexes to a given Accpac table if the situation warrants it?

I undrstand the downside that: a) additional indexes can slow down other functions (such as updates) on a large table, and 2) they’ll be lost in a DBDUMP/DBLOAD and would have to be re-created manually.

It is acceptable. Like you said, you just need to be aware that sometime they will be removed (dbload, activation). Adding an index can improve the speed of searches if there is something you need to frequently search on.